A general vessel is equipped with an internal combustion engine such as a diesel engine, for multiple purposes such as generation of propelling power for a vessel or generation of electrical power used in a vessel.
In the internal combustion engine, generally, strokes of intake, compression, explosion, and exhaustion are used to generate power. In a fuel intake process, intake air is introduced with fuel into the inside of the internal combustion engine. An efficiency of the internal combustion engine may be increased by increasing pressure of the intake air.
Accordingly, a vessel equipped with a turbocharger for supplying a large amount of intake air by increasing pressure of the intake air has been recently suggested.
An intake air compression method using the turbocharger includes a supercharger method of mechanically driven by engaging a toothed wheel to a crank shaft of the internal combustion engine and a turbocharger method that is driven by an exhaust turbine using an exhaust gas generated from the internal combustion engine.
FIG. 1 illustrates an example of a vessel equipped with a turbocharger for compressing an intake air by a turbocharger method.
When an exhaust gas E having certain pressure and temperature is discharged from an internal combustion engine, that is, an engine 310, of the vessel, the exhaust gas E is supplied to a turbocharger 100.
In this state, a rotational force is generated in an exhaust turbine 111 by the energy of the exhaust gas E supplied to the turbocharger 100. The rotational force is transferred to a compression turbine 112 connected to the exhaust turbine 111. The compression turbine 112 compresses an external intake air “a” and supplies the compressed air to the engine 310, by using the rotational force.
In the turbocharger 110, the intake air “a” is compressed in a compression process according to an adiabatic compression process. Thus, a temperature of the intake air “a” after the compression, that is, a temperature of the intake air “a” at a rear end side of the turbocharger 110 increases compared to a temperature of the intake air “a” before the compression, that is, a temperature of the intake air “a” at a front end side of the turbocharger 110.
In general, as the temperature of the intake air “a” supplied to the engine 310 that is the internal combustion engine increases, the efficiency of the engine 310 decreases. In this regard, as the temperature of the intake air “a” at the rear end side after passing through the turbocharger 110 increases, the efficiency of the engine 310 is degraded.
Further, when the vessel is operated in a high temperature environment such as in tropical regions, the intake air “a” is compressed from the front end side of the turbocharger 110 in a state in which the temperature of the intake air “a” is increased, and thus, the efficiency of the engine 310 is further degraded.